# Process constraints

> [!NOTE]
>
> Process constraints in PeopleStage have been developed to support [triggered events](<https://help.apteco.com/en/orbit/campaigns/journey-builder/journey-steps/triggered-events/index.md>) in Orbit campaigns.

We've long been able to group steps into a process in PeopleStage. However, you can now apply a process constraint.

Process constraints control the number of instances that a person can be in a group at any given time. This constraint overrides the default single-person constraint for a campaign.

There are two types of process constraint:

- Contact strategy
- Instance constraint

## Contact strategy

You can apply a contact strategy and set up as usual, e.g. one communication per month or one group per timeframe.

As we have grouped the message and audience together to make a process, we call this a Group constraint. This means recipients can be prevented from entering the group (process) if they have already been in it within the specified timeframe.

## Instance constraint

An instance constraint controls how many times we can move a recipient into a process.

You can only apply an instance constraint to a process and works as follows:

- If the instance constraint is set to 1, and the recipient is eligible, they move from the main campaign flow into the process and exit the campaign
- If the instance constraint is set to greater than 1, the recipient can be cloned, allowing them to remain in the main campaign flow while also moving through the process

> [!NOTE]
>
> **Explainer: Process constraints**
>
> In Orbit, triggered events are set up as part of the campaign but operate alongside the main campaign flow.
>
> You can use a live data audience or standard audience as a starting point for a triggered event and a message can be added.
>
> When a user creates an Orbit campaign containing a triggered event, it is supported in PeopleStage with a process.
>
> When the process runs, it only processes recipients in the main campaign flow.
>
> As a result of triggered events in Orbit, both a contact strategy and instance constraint can now be applied to a process and viewed in PeopleStage.